For personal cleaning care appliances, such as the electric toothbrush, the electric shaver, the electric face cleansing instrument, the electric shower and the like, it is important to have a personal cleaning care appliance which can convert the reciprocating motion into a desired rotary motion of a cleaning element, and these personal cleaning care appliances should be simple in structure, convenient to assemble, long in service life, and safe and reliable.
There are known a number of driver configurations for driving the cleaning elements, such as motors, magnetic systems and electromagnetic systems. Some driver configurations employ bearings (such as ball bearings) to support the driver, and such configurations are both expensive and complicated, and also have noise and motor damping.
CN 100591301C discloses a device for converting a lateral motion into a rotary motion of the work piece of the appliance, wherein the drive assembly comprises an electromagnet which is capable of generating a lateral force and engages with two permanent magnets in operation, and the permanent magnets are fixed to the moveable end pieces located at the rear end of the motion conversion assembly, so as to move the end piece in a side-to-side slightly arcuate translation manner. The two permanent magnets are relatively fixedly mounted onto the end pieces. The motion conversion assembly converts the driving action of the drive assembly into a twisting or rotating action of the drive shaft through the provision of a leaf spring, and the drive shaft then rotates the brush head arm and the brush head such that they rotate around the longitudinal axis of the drive shaft. CN 101297775B discloses a method for adjusting the elastic elements of a resonant driving system, wherein the spring elements are not curved, and their resonant frequency is changed by sufficiently altering the stiffness of the elastic elements so that the resonant vibration frequency is very close to the driving frequency of the appliance.